The present invention relates to patient support systems and more particularly to a low air loss patient support system.
Patients confined to beds for long periods of time must be turned frequently to rest on different portions of their bodies in order to avoid the onset of bed sores or to alleviate discomfort associated with same. Turning the patient also helps avoid accumulation of fluid in the lungs. Heretofore, turning a patient has been a labor intensive task of the hospital staff, and the rising cost of hospital staff has made this task ever more expensive for the hospital and ultimately the patient.
Though not a low air loss bed, one apparatus and method of turning a patient is disclosed in U.S. Pat. No. 3,485,240 to Fountain. The apparatus has cushions 11, 12, which overlap one another substantially so that substantially the patient's entire body may be accommodated by each pad. Each cushion is normally not inflated when the patient rests horizontally on the bed. Each cushion has a surface that can be inclined when inflated. A mechanism 30 individually inflates and evacuates cushions 11, 12 and includes an outlet switch 31, a timer 32, and a four-way valve 33. In one position, valve 33 connects cushion 11 to a vacuum to evacuate same and cushion 12 to a pump to inflate same. In a second position, cushion 12 is connected to the pump and cushion 11 is connected to the vacuum. The timer controls the sequence of alternating between the two positions of valve 33. Each cushion can be segmented to permit different segments to be inflatable to a different degree or contour.
In order to prevent slippage of the patient on the inclined surface of the Fountain cushions, the patient is required to be confined by straps 41, 42 around the patient's legs for example. This constraint becomes useless if the patient is an amputee and is detrimental to the healing process if the patient has sores or wounds on the legs or other portions of the body that would be constrained by the straps. Moreover, such straps are uncomfortable and interfere with the ability of the patient to repose restfully. Furthermore, the inflation and evacuation mechanism 30 does not permit a steady state of partial evacuation of cushions 11, 12, requiring instead either total deflation or total inflation during the steady state of operation that occurs once inflation and evacuation is complete.
Another apparatus and method for automatically turning a patient confined to a low air loss bed is disclosed in European Patent Application Publication No. 0 260 087 A2 to Vrzalik. To eliminate the need for confinement straps, this apparatus provides a retaining means by specially configuring the shape of air bags mounted transversely on a frame. In one embodiment, this retaining means takes the form of a pillar which is integral with each air bag and which, when inflated, projects upwardly to form the end and corner of the air bag. The means for moving the patient toward one side of the frame when the substantially rectangular Vrzalik air bag is inflated includes a trapezoidal-shaped cutout in the top of the air bag and disposed between the center of the bag and only one end of the bag. The bags are disposed on the frame so that adjacent bags are disposed with the cutout toward opposite sides of the frame. All the bags with the cutout on one side of the frame define a first set of bags, while the bags with the cutout on the opposite side of the frame define a second set of bags. When the first set of bags is inflated while deflating the second set, the patient is moved to one side of the bed.
The Vrzalik device also includes an air control box that is interposed in the flow of air from a gas source to a plurality of gas manifolds that connect to the air bags. The air control box has individually adjustable valves for changing the amount of gas delivered to each of the gas manifolds. Each of the valves is individually adjustable to change the amount of flow from the gas source through the air control box to each of the gas manifolds. The air control box also has means for heating the gas flowing through it. A heat sensor is disposed in one of the gas manifolds and is operable so that the heating means is controlled by signals therefrom.
The patient care industry has become sensitive to the patient's psychological reaction to the environment of life support machinery. Complex machinery such as shown in Vrzalik FIGS. 1 and 6 tends to remind the patient of the patient's precarious health and the heroic and expensive technological effort that is required to sustain the patient. Accordingly, it becomes desireable to minimize the visibility of connecting tubing and hosing such as shown in Vrzalik FIG. 6 so that the patient support system more closely resembles the bed in which the patient sleeps when at home.
A low air loss patient support requires maintenance by both technical personnel and hospital personnel. The cost of providing such maintenance is directly proportional to the time required to perform such maintenance.